Project Summary Accurate and real-time blood alcohol monitoring has major implications for research on alcohol use and abuse, and for personal and public health. Intelligent Optical Systems (IOS) proposes to develop a wearable, minimally- invasive subdermal alcohol concentration (SubDAC) monitor based on specific but non-enzymatic detection. The SubDAC monitor will combine two key innovations to overcome the challenges faced by other wearable alcohol monitors: (1) a novel luminescent material developed by IOS under a contract with NASA for specific detection of alcohols, designed for the long-term stability requirements of space missions, and (2) a low-cost microneedle array for subdermal detection to minimize physiological lag time. IOS has recently developed highly specific luminescent sensor materials for volatile alcohol detection. The heart of a luminescent optical chemical sensor is the sensitive material, a polymer in which a specific luminescent indicator molecule has been immobilized. In response to a selective and reversible interaction between the target analyte (ethanol) and the indicator, the luminescence of the sensitive material undergoes a measurable change proportional to the analyte concentration. In these solid state sensors, there is no consumption of any reactant, and the sensor elements can last for years. In addition, IOS has developed a low-cost method of producing microneedle arrays using direct laser writing. The manufacturing technique is highly versatile, allowing for customization of microneedle geometry and mass production of microneedle arrays. In Phase I, we will optimize our sensor chemistry for sensitivity to physiologically relevant alcohol concentrations, incorporate this chemistry into a biocompatible polymer suitable for microneedle array formation, and demonstrate continuous alcohol detection in the target range in-vitro. In Phase II a wearable electronic device will be assembled, and in-vitro testing extended. Safety will be tested in animal models. An Investigational Device Exemption (IDE) from the U.S. Food and Drug Administration (FDA) will be obtained, and clinical studies will be initiated. The ultimate result of this work will be a discrete, wearable device, the size of a wrist watch or fitness tracker, capable of accurate, real-time blood alcohol concentration monitoring. The device will be marketed to individuals for quantifying short-term blood alcohol and tracking long-term behavior; it will be useful to researchers studying the epidemiology of alcohol abuse, and may have applications in court-mandated abstinence programs.